A dual camera generally includes a wide-angle camera and a telephoto camera, and can achieve a zoom. A zoom ratio depends on a ratio of a field angle of the wide-angle camera to a field angle of the telephoto camera. The wide-angle camera is usually used as a main camera, and in order to guarantee the quality of shooting, the field angle cannot be too large, so the field angle of the telephoto camera needs to be narrowed, which leads to a too large focal length of the telephoto camera and thus an excessive height thereof, such that when the dual camera is applied in a mobile phone, it is not conductive to making the mobile phone lighter and thinner.